A. It isn’t necessary to wear anything underneath your wetsuit but you may find that a rash vest feels more comfortable than nothing at all. Wet suits can rub sensitive skin and cause rashes and abrasions, so wearing a rash vest creates a good barrier between you and the suit.
Wearing a rash vest under your wetsuit, however, will not keep you warmer. If you do decide to wear a rash vest under your wetsuit, make sure it fits tightly to your body.
If you are renting your wetsuit, it is advisable to wear a swimming costume, at least, underneath for hygiene reasons.
